Watershed dynamics

Mitchell MJ, Bailey SW, Shanley JB et al (2008) Evaluating sulfur dynamics during storm events for three watersheds in the northeastern USA a combined hydrological, chemical and isotopic approach. Hydrol Process 22 4023 034... 

Webster JR, Patten BC (1979) Effects of watershed perturbation on stream potassium and calcium dynamics. Ecol Monogr 49 51-72... 

Tardy Y, Bustillo V, Boeglin JL (2004) Geochemistry applied to the watershed survey hydrograph separation, erosion and soil dynamics. A case study the basin of the Niger River, Africa. Appl Geochem 19 469-518... 

Similarly to N, most S pools are found in organic form in forest floor and soil humus. However, unlike nitrogen, there are important abiotic processes, especially sulfate sorption processes, which play a critical role in regulating sulfate dynamics in forest ecosystems. An example of this type of exposure pathway was shown in the Habbard Brook whole-tree harvesting experiment, where the decrease in sulfate output from the watershed was attributed to sulfate adsorption, which was enhanced by soil acidification from nitrification (see above). 

The input of airborne lead to the Forest ecosystems has been studied at the Hubbard Brook Experimental Forest in New Hampshire. The small catchment approach has been used to study the lead biogeochemical cycle since 1963 (Likens et al., 1977 Driscoll et al., 1994). By monitoring precipitation inputs and stream output from small watersheds that are essentially free of deep seepage, it is possible to constmct accurate lead mass balance. The detailed study of soil and soil solution chemistry and forest floor and vegetation dynamics supplemented the deposition monitoring. 

Sthapit KM (2005) Sedimentation of lakes and reservoirs with special reference to the Kulekani Reservoir. In Schreier H, Shah PB, Brown S (eds) Challenges in mountain resource management in Nepal. Processes, trends and dynamics in Middle Mountain Watersheds. ICIMOD Publ, Kathmandu, pp 5-12... 

Shrestha B, (2000) Population dynamics and land use in the Yarsha Khola Watershed. In Allen et al (ed) The people and resource dynamics project 1996-1999. International Center for Integrated Mountain Development and IDRC, p 75-83... 

Past lake-water chemistry changes can be determined by comparison of historical with current measurements hindcasts using empirical and dynamic computer models space-for-time substitutions (i.e., comparisons between the affected lakes and similar but unaffected lakes) and paleolimnological studies. Of these, paleolimnology is the only approach that does not require the existence of historical data or a thorough understanding of all important watershed and in-lake biogeochemical processes. 

Inland water systems are more diverse and dynamic than marine systems (see Chapter 18) therefore, it becomes apparent that more emphasis should be placed on understanding microbial community dynamics in these highly variable systems. Lakes and rivers are intimately associated with their watersheds and hence receive a large influx of material from the surrounding terrestrial environments. This linkage affects the biogeochemical cycles and processes within the system as oftentimes members of the terrestrial community end up in the aquatic environment. 

Consideration of the impact of low-frequency fluctuations of climate on Caspian Sea level showed that the long-term variability of the level is connected mainly with SST anomalies in the eastern part of the tropical Pacific Ocean. It turns out that positive SST anomalies correlate with the growing rain rate in the Volga River watershed basin and vice versa. The main reason for variations in Caspian Sea level is the long-term dynamics of El Nino events, which should be considered as chaotic. 

Tufekcioglu, A., J.W. Raich, T.M. Isenhart, and R.C. Schultz (2003). Biomass, carbon and nitrogen dynamics of multi-species riparian buffers within an agricultural watershed in Iowa, USA. Agroforest. Syst., 57(3) 187-198. 

It has been estimated that riverine and atmospheric N inputs in the North Atlantic Ocean basin are at least equal to and may exceed N inputs by biological N2 fixation (Howarth et al., 1996 Paerl and WhitaU, 1999). Therefore, our understanding of marine eutrophication dynamics needs to consider a range of scales including ecosystem, watershed, regional and global. 

Page, H. M., Petty, R. L., and Meade, D. E. (1995). Influences of watershed runoff on nutrient dynamics in a southern Cahfornia salt marsh. Estuar. Coast. Shelf Sci. 41, 163—180. 

Intensive investigations of the sulfur dynamics of forest ecosystems in the last decade can be attributed to the dominant role of sulfur as a component of acidic deposition. Studies in forested catchments include Fuller et al. (1986), Mitchell et al. (1989), Stam et al. (1992), and Andersson et al. (1992). Sulfur with a distinctive isotopic composition has been used to identify pollution sources (Krouse et al., 1984), and has been added as a tracer (Legge and Krouse, 1992 Mayer et al., 1992, 1993). Differences in the natural abundances can also be used in systems where there is sufhcient variation in the 5 " S of ecosystem components. Rocky Mountain lakes (USA), thought to be dominated by atmospheric sources of sulfate, have different 5 " S values than lakes believed to be dominated by watershed sources of sulfate (Turk et al., 1993). 

Novak M., Kirchner J. W., Groscheova H., Havel M., Cemu J., Krejcf R., and Buzek F. (2000) Sulphur isotope dynamics in two central european watersheds affected by high atmospheric deposition of SO. Geochim. Cosmochim. Acta 64, 367-383. 

Pickle, J.D., 1985, Dynamics of clastic sedimentation and watershed evolution within a low-relief karst drainage basin. Mammoth Cave Region, Kentucky, MS Thesis, University of New Mexico, Albuquerque, 147 pp. 

Mountain forests that become organized in the vertical bands just described harbor the majority of plant biomass on elevated terrain and are of major importance to the maintenance of montane ecosystems and watersheds. Coarsely, they have more or less well defined lower and upper altitudinal boundaries. These limits possess widely different dynamics. 

Meyer, J. L. and Tate, C. M. (1983). The effects of watershed disturbance on dissolved organic carbon dynamics of a stream. Ecology 64, 33-44. 

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